The present invention relates in general to improvements to air powered tools and, in particular, to improvements to air powered tools that have an air motor having an integral generator (integrated air motor generator or IAMG).
An air tool with an air motor having an integral generator is disclosed in U.S. Pat. No. 4,678,922 issued on Jul. 7, 1987 to the inventor of the present invention. U.S. Pat. No. 4,678,922 is hereby incorporated by reference. FIG. 12 shows the side-pole arrangement of the air motor and integral generator of the '922 patent. As shown in FIG. 12, the side-pole arrangement includes a bearing 139 at the working end of the tool, a bearing end plate 178, an insulating ring 142, coils 180, a magnet rotor 174 having magnets 176, an air chamber 134, a rotor shaft 146, a rotor body 148, fins 150, a bearing end plate 152, a bearing 154 and a retaining ring 156.
In the side-pole arrangement of FIG. 12, the magnet rotor 174 and coils 180 are positioned between the working end of the air tool and the rotor body 148. In such a position, it has been found that the magnet rotor 174 and coils 180 are subjected to a large a mount of vibrations transmitted from the working end of the tool. These vibrations are freely transmitted directly to the permanent magnets 176 in the magnet rotor 17 thereby causing detrimental changes in the magnetic properties (magnetic disorientation) over time. This magnetic disorientation results in diminished energy from the magnetic circuit and consequent diminished electrical output from the generator.
Another problem associated with the prior art side-pole arrangement is overheating of the coils 180. Overheating of the coils 180 causes the specific resistance of the current carrying conductors (wire) comprising the coils to increase thereby diminishing the electrical output of the generator.
FIG. 13 shows a prior art air tool 310 having rechargeable batteries 332, a handle 326, an air motor 318, a shaft 320, a casing 314, a disc 322, a lever 324, an air hose 312, an air hose fitting 316, a gooseneck 330 and a lamp 328.
A problem with the air tool of FIG. 13 is that the gooseneck lamp 330, 328 must be frequently adjusted to provide adequate lighting to the work surface. The gooseneck lamp 330, 328 also undesirably adds to the overall exterior dimensions of the air tool 310 thereby making it more difficult to work in cramped areas.
There has also been a need to provide smaller air tools which can generate the same amount of or more electricity than a larger tool. Smaller tools are desirable for working in smaller areas and for reducing the amount of materials required for manufacture of the tool. Increased power capability is desirable to provide better lighting and to enable other electrically driven devices to be powered by the integral air motor generator.
Another problem with the prior art air motors with integral generators is determining whether or not the generator is functioning properly. That is, if the generator malfunctions and power begins to be drawn from the batteries, it is desirable to know that the generator is malfunctioning prior to complete discharge of the batteries and consequent total loss of electric power.
Still another problem with the prior art is determining when the movable air vanes 150 (FIG. 12) are not adequately lubricated. Inadequate lubrication of the vanes 150 results in excessive wear to components of the motor, decreased power output and possible seizing of the motor. Therefore, it is desirable to have an indication of the lack of adequate lubrication prior to any damage to the tool.
A problem with air tools that do not have an integrated generator is that of providing adequate lighting to the work area. Battery packs or separate lighting devices are heavy in weight and increase the number of separate items that must be transported to a work area.